1. The problem statement, all variables and given/known data Hello, I have derived the equation for the gravitational force for a disk to be 2Ggm/a^2(1-x/sqrt(a^2 - x^2) when an object is added on top of the system. My question is would the force still be somewhat similar if the disk now had a small hollow of radius c and from the center to the end of the disk the distance is d? 3. The attempt at a solution Im assuming it will be and that the only difference I would make is that my radius is now (d-c) or my new area would now be da = 2 * pi * (d^2 - c^2) but im not sure if that logic makes sense.